Author Topic: DUO modding help(or repairing)  (Read 73 times)

geo

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DUO modding help(or repairing)
« on: November 18, 2021, 08:52:46 PM »
Hi

I just bought a duo from Japan. Well, it says "not reading CD". After receiving, I also found low PCM volume.
Then I recapped the console and bought new lens. Now it's reading CD-ROMs but this time all sounds disappear. Lifted 4558s for some cleaning, and nothing changed.
(IC503 got only 1V power, and so does IC506, the chip besides AV jack)

I do believe that there's some corruption causing this problem, but instead of finding the corruption(It really takes long), I'm thinking of an audio mod.
Is it possible to get audio signal from motherbord, then output them to an amp outside the system, not the audio jack?

Thanks a lot. :)
« Last Edit: November 18, 2021, 08:55:18 PM by geo »

HuDuo

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Re: DUO modding help(or repairing)
« Reply #1 on: November 21, 2021, 03:08:27 PM »
The 4558 op amps don't need leakage underneath them to stop working, they can fail and not look bad externally. You must check the op amps with a volt meter to see what the input and output voltages are. If the output voltages are too low on any of the op amps, you'll have to replace them.

Another thing that can cause low voltage in the audio circuit is corroded vias, those are parts of traces where it ends in a hole that transitions the trace from one side of the board to another. You will have to look over the whole audio amp section of the board for corroded vias.

Keith Courage

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Re: DUO modding help(or repairing)
« Reply #2 on: November 22, 2021, 04:29:42 AM »
It's much easier to actually replace caps, and repair the bad traces and components on the board than it would be to build a new amp for a DUO.

Start checking traces and via holes for shorts.